The kinematics of Ny-Alesund from space geodetic data | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS

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  The kinematics of Ny-Alesund from space geodetic data

Type de publication:

Journal Article

Source:

Journal of Geodynamics, Volume 48, Ticket 1, p.37-46 (2009)

ISBN:

0264-3707

Numéro d'accès:

WOS:000267567500005

URL:

http://www.sciencedirect.com/science/article/pii/S0264370709000404

Mots-clés:

UMR 7154 ; Géophysique spatiale et planétaire ; N° Contribution : 2498 ; Ny-Ålesund; VLBI; GPS; DORIS; Tide gauge; Reference frame

Résumé:

We have compared coordinate time series from several space geodetic observing techniques to derive the kinematical motions of Ny-Alesund, Svalbard. Velocity estimates from VLBI, GPS, and DORIS scatter more than the expected error estimates from each technique, and also between individual GPS solutions with different software and analysis strategies. A statistical combination yields average topocentric velocity components of 14.3 +/- 0.2 mm/year (north), 9.8 +/- 0.7 mm/year (east), and 8.2 +/- 0.9 mm/year (vertical) for 1993-2007. The horizontal velocity is in agreement with a combined prediction of NUVEL-NNR-1A and the effects of post-glacial rebound and present day ice melt of nearby glaciers. The observed uplift is twice that predicted by the two latter processes. The non-linear time series of both VLBI and GPS data suggest that the uplift rate increases from 7.0 mm/year before 2003 to 10.8 mm/year after 2003. We conclude that this has a geophysical origin since no monument motions have been detected. A recent sea level decrease (1993-2007) of 4.7 +/- 0.9 mm/year supports an absolute sea level increase of 3.2 mm/year as determined elsewhere by satellite altimetry. (C) 2009 Elsevier Ltd. All rights reserved.